Security inspection systems are widely used in stations, subways, airports, customs, ports, nuclear power stations, government offices, postal inspection centers, courts, meeting places and the like since they have small sizes, light weights, low power consumption and improved self-diagnosis functions and thus can be conveniently operated and maintained.
Since X-rays generated by security inspection machine in operation will affect the health of operators, lead curtains are usually installed at both ends of a housing of the security inspection machine to serve as shielding curtains to shield the X-rays in security inspection channels and prevent the X-rays from spreading out to cause potential damage to surrounding people.
Currently, lead curtains mainly comprise fixed lead curtains and movable lead curtains. As a typical example, the movable lead curtain is in a roller-rotation form. Generally, existing lead curtains are fixedly suspended at entrances and exits of the security inspection channels. In a general security inspection process, an article to be detected is conveyed by a conveyor belt to push a lead curtain at the entrance to enter a detection zone, and after being detected, the article is conveyed by the conveyor belt to push a lead curtain at the exit to leave the detection zone.
In practical application of fixed lead curtains, since the lead curtain is relatively heavy, some lightweight articles to be detected cannot push the lead curtain to enter the detection zone, which brings unnecessary troubles. Furthermore, when the lead curtains are pushed open, the X-rays will inevitably spread out.
For a lead curtain device in the roller-rotation form, intervals between adjacent lead curtains are fixed and cannot be adjusted. In one way, the arrangement of the articles to be detected shall adapt to the fixed intervals between the lead curtains. Accordingly, the articles to be detected should be deliberately placed to adapt to the fixed intervals between the lead curtains, which results in low detection efficiency and time waste. In another way, the lead curtains shall be densely arranged along the conveyor belt, instead of deliberately arranging the articles to be detected to adapt to the fixed intervals between the lead curtains. However, this way results in that the entire transmission system is very heavy, thereby causing great energy waste. Moreover, it cannot be guaranteed that a lead curtain in the entire channel is precisely located in the space between the articles to be detected, and in this case, the rays will spread out.
Furthermore, the transmission of the roller-type conveyor belts has obvious disadvantages. That is, in practical application, the lead curtains cannot be easily and effectively fixed on the conveyor belts. The current customized conveyor belts have no interface to connect with external devices and need to be retrofitted, so that the high cost will make mass production unfeasible. Besides, in the practical application, if the intervals between the rollers are too large, when the lead curtains are densely distributed, the weights of the lead curtains will inevitably cause a serious downward deflection of the conveyor belts, resulting in greatly reduced article transfer and X-ray shielding effects.
Therefore, there is needed an improved ray shielding method for detecting device and a lead curtain protective device.